L8: Epithelial Tissue (onaizi) Flashcards
“A diverse group of cells with an ordered structure working together for a common function”
Shnu hatha?
Tissue
What are the 4 types of tissue?
- Epithelial - the lining of our body
- Connective
- Muscle
- Nervous
What are the basic characteristics of epithelial tissue?
- Covers body surface
- Lines body cavities
- Forms glands
- Highly regenerative
- Avascular
Shlon shakl il epithelial tissue?
Closely packed cells- has little extracellular surface
Cells are joined by specialized cell-to-cell junctions
What are the glands that epithelial tissue forms?
Skin
Airways
Digestive lining
Urinary tract lining
Which tissue type is avascular?
Epithelial tissue
(Haman cartilage)
Describe the basement membrane of epithelial tissue
• Separates epithelium from underlying connective tissue
• It is a non-cellular membrane comprised
of polysaccharide rich membrane apical surface
• Acts as a sieve to prevent materials from
entering the body
Epithelial tissue:
Free surface is the ________ and the bound
surface is the ________ side
apical side
basolateral
What are some of the functions of the epithelial tissue?
Some epithelial cells, based on their location, have
specialized cells on them to help them carry out their functions
Give me some examples of these specialized cells and their functions:
Name:
- The different cell shapes and layers in epithelial tissue
- The surface specialization of each of these cell shapes
Compare cilia and microvilli
Where do you find simple squamous epithelium in the body?
- Makes up the alveoli (air sacs of the lung)
- Makes up the lining of all blood vessels and capillaries (endothelium)
- Make up various membranes within the body (peritoneum)
- Glomerulus of kidney
Where do you find simple cuboidal epithelium?
It makes up the collecting (dnt forget it helps with absorption) tubules of the:
1. Kidney
2. Liver
3. Pancreas
4. Thyroid
5. And other glands of the body
= synthesis of hormones
Where do you find simple columnar ciliated? + why is it in that structure?
It makes up the lining of the ovary ducts (fallopian tube)
It helps with motility; y7arik il sperm
ONLY FOUND IN THE FEMALE REPRODUCTIVE TRACT
Where do you find simple columnar microvilli epithelium with goblet cells?
W laish fee goblet cells?
It is found in the GI tract/lining of the intestine
Fe goblet cells to secrete mucus
Where do you find stratified squamous epithelium?
In areas of the body prone to abrasion:
keratinizing: skin
non keratinizing: oral cavity, esophagus, vaginal wall, anal canal
Where do you find keratinizing and non-keratinizing stratified squamous epithelium?
Keratinizing stratified squamous epithelium: skin
Non-Keratinizing stratified squamous epithelium: tongue, oral mucosa, esophagus, vagina, anal canal
What is keratin? (Its composition and its function)
Dead skin cells that change their morphology and are purely composed of a protein that acts as a protective barrier (for example bl skin)
Where do you find stratified cuboidal epithelium?
W shnu its function?
- found in: Sweat glands, salivary glands, ovarian follicles and seminiferous tubules
It has a similar role to simple cuboidal cells, which is secretion: Secretes sweat, ovarian hormones and sperm
Which type of epithelial tissue is rare?
Stratified columnar epithelium
Epthelia are classified according to cells…..?
nearest to the lumen (so the apical surface)
Where is stratified columnar epithelium located?
Located in the largest ducts of salivary glands:
1. parotid
2. submandibular
The basal layer of cells are cuboidal cells and the layer nearest the apical surface includes columnar cells. The large droplets are mucus, in Goblet cells.
What is the main role of goblet cells?
To secrete mucus
Where do u find pseudo stratified columnar ciliated epithelium with goblet cells?
Shnu its function?
- Makes up the lining of the respiratory tract
Functions:
1. Secretes mucus
2. Moves mucus
3. Traps foreign particles
In which layer does cell division/nourishment come from in epithelial cells?
They come up from the basal level, whereas in transitional cells yee mn the top layer
Where do you find transitional epithelium?
Shnu il characteristics?
Found in: lining of the bladder and the ureter
Characteristics:
1. Can expand and distend
2. Bi-nucleated cells (cells are dividing)
3. Multi layered/ stratified
4. Top layer cuboidal + bottom layer mixed
What type of epithelial cells make up the upper respiratory tract
Pseudo-stratified columnar ciliated epithelium
(stereocilia is in the epididymis based on the lab notes, dont mix them up)
Is stereocilia a type of cilia? And are they motile?
